JP2010104203A - Power feed control apparatus, power feed apparatus, electric power-receiving control apparatus, electric power-receiving apparatus, electronic equipment, and contactless power transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform proper contactless power transmission in accordance with feedback information at a power-receiving side. <P>SOLUTION: A power feed control apparatus 20 is installed in a power feeding apparatus 10 of a contactless power transmission system which transmits power from the power feeding apparatus 10 to a power-receiving apparatus 40 by magnetically connecting a primary coil L1 and a secondary coil L2, and feeds the power to the load of the power-receiving apparatus 40. The power feed control apparatus 20 includes a controller 22 to control the power feeding apparatus 10. The controller 22 has a receiving processor 34 to receive feedback information at the power-receiving side from the power-receiving apparatus 40; a transmission parameter setting unit 32 to set a transmission parameter on a transmission side to obtain an optimal load value, which maximizes a power feed efficiency in the combination of the primary coil L1 and the secondary coil L2, on the basis of the feedback information on the power-receiving side; and a power feed controller 31 to perform power feed control on the basis of the transmission parameter on the power feed side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power transmission control device, a power transmission device, a power reception control device, a power reception device, an electronic device, a contactless power transmission system, and the like.

  In recent years, contactless power transmission (contactless power transmission) that uses electromagnetic induction and enables power transmission even without a metal part contact has been highlighted. Charging of telephones and household equipment (for example, a handset of a telephone) has been proposed.

There is Patent Document 1 as a prior art that performs such contactless power transmission. In Patent Document 1, in order to stabilize the supplied power, the power transmission side varies the waveform duty on the power transmission side based on feedback information from the power reception side, thereby keeping the output of the drive voltage to the power reception side constant. .
JP 2007-336717 A

  However, when the load on the power receiving side is a battery or the like, the value of the optimum load fluctuates due to charging / discharging, and in the prior art of Patent Document 1, feedback control considering the power receiving side optimum load has not been sufficient. .

  According to some aspects of the present invention, it is possible to provide a power transmission control device, a power transmission device, a power reception control device, a power reception device, and an electronic apparatus that can execute appropriate contactless power transmission.

  One aspect of the present invention is a contactless power transmission that electromagnetically couples a primary coil and a secondary coil to transmit power from a power transmitting device to a power receiving device and supply power to a load of the power receiving device. A power transmission control device that controls the power transmission device of the system, the control unit including a control unit that controls the power transmission control device, wherein the control unit receives reception-side feedback information from the power reception device, and the power reception A transmission parameter setting unit for setting a power transmission side transmission parameter for obtaining an optimum load value that maximizes the efficiency of power transmission in the combination of the primary coil and the secondary coil based on side feedback information; And a power transmission control unit that performs power transmission control based on transmission parameters.

  According to one aspect of the present invention, based on the power receiving side feedback information received from the power receiving side, the power transmission side transmission parameter for obtaining the optimum load value that maximizes the power transmission efficiency is set, and the power transmission side transmission parameter is set. Since the power transmission control is performed based on the power transmission, proper power transmission corresponding to the power receiving side feedback information can be performed.

  In one aspect of the present invention, the transmission parameter setting unit sets the power transmission side transmission parameter so that a load value of the load of the power receiving device obtained from the power receiving side feedback information approaches the optimum load value. It is good.

  In this way, since the transmission parameter setting unit sets the power transmission side transmission parameter so that the load value of the load of the power receiving device obtained based on the power reception side feedback information approaches the optimum load value, 2 from the primary side. Power transmission to the next side can be maintained at maximum efficiency.

  In the aspect of the invention, the transmission parameter setting unit may set at least one of a driving voltage and a driving frequency of the primary coil as the transmission-side transmission parameter.

  In this way, power transmission from the primary side to the secondary side can be maintained at maximum efficiency by using at least one of the drive voltage and drive frequency of the primary coil as the power transmission side transmission parameter.

  Moreover, in one aspect of the present invention, the reception processing unit receives the power receiving side feedback information after starting normal power transmission of the power transmission device, and the transmission parameter setting unit is configured to transmit the power transmission side based on the power receiving side feedback information. Transmission parameters may be set.

  In this way, even if the load on the secondary side changes after the start of normal power transmission, power transmission from the primary side to the secondary side can be maintained at maximum efficiency.

  In the aspect of the invention, the reception processing unit receives the power receiving side feedback information in a periodic authentication period after the start of normal power transmission, and the transmission parameter setting unit is configured to transmit the power transmission based on the power receiving side feedback information. The side transmission parameter may be set.

  In this way, since the power transmission side transmission parameters are set based on the power receiving side feedback information transmitted from the power receiving side using the signal transmission due to the load fluctuation in the regular authentication period after the start of normal power transmission, more power receiving side Appropriate power transmission corresponding to the feedback information can be performed.

  In one aspect of the present invention, the reception processing unit receives the power receiving side feedback information before starting normal power transmission of the power transmission device, and the transmission parameter setting unit includes the power receiving side feedback information before starting normal power transmission. Based on this, the power transmission side transmission parameter after the start of normal power transmission may be set.

  In this way, it is possible to perform proper power transmission corresponding to the power receiving side feedback information after starting normal power transmission.

  In the aspect of the invention, the reception processing unit receives at least one of information on output voltage to the load on the power receiving side and information on load current flowing in the load as the power receiving side feedback information. It is good to do.

  If it does in this way, appropriate electric power transmission corresponding to the change of the information of the output voltage to the load by the side of power reception, and the load current which flows into load will be attained.

  In one aspect of the present invention, the transmission parameter setting unit sets the transmission-side transmission parameter so that a load value of the load obtained based on the power-receiving-side feedback information approaches the optimum load value. It is good.

  In this way, by setting the power transmission side transmission parameter so that the load value of the load of the power receiving apparatus obtained by the transmission parameter setting unit based on the power receiving side feedback information approaches the optimum load value, the secondary side from the primary side Power transmission to the side can be maintained at maximum efficiency.

  In one aspect of the present invention, the transmission parameter setting unit controls the lowering of the driving voltage of the primary coil and the raising of the driving frequency of the primary coil when the load value is smaller than the optimum load value. It is good also as performing at least one of these.

  Thus, when the load value is smaller than the optimum load value, at least one of control for lowering the drive voltage of the primary coil and control for raising the drive frequency of the primary coil is performed, so that the load value becomes the optimum load value. Therefore, power transmission from the primary side to the secondary side can be maintained at the maximum efficiency.

  In the aspect of the invention, the transmission parameter setting unit may control the driving voltage of the primary coil to be increased and the driving frequency of the primary coil to be decreased when the load value is larger than the optimum load value. It is good also as performing at least one of these.

  As described above, when the load value is larger than the optimum load value, the load value is set to the optimum load value by performing at least one of the control for increasing the drive voltage of the primary coil and the control for reducing the drive frequency of the primary coil. Therefore, power transmission from the primary side to the secondary side can be maintained at the maximum efficiency.

  In the aspect of the invention, the transmission parameter setting unit may set the power transmission side transmission parameter by a conversion processing table that converts the power receiving side feedback information into the power transmission side transmission parameter.

  Thus, since the power transmission side transmission parameter is varied from the power receiving side feedback information by the conversion processing table, the power transmission from the primary side to the secondary side can be maintained at the maximum efficiency.

  In one aspect of the present invention, the reception processing unit receives, as the power receiving side feedback information, information on an output voltage to the load on the power receiving side and a load current flowing through the load, and the transmission parameter setting unit includes: At least one of the driving voltage and driving frequency of the primary coil is set as the transmission-side transmission parameter, and the conversion processing table is configured to determine the driving voltage of the primary coil based on the output voltage and the load current information. In addition, at least one of the drive frequencies may be output.

  In this way, since at least one of the drive voltage and drive frequency of the primary coil is varied based on the output voltage and load current information by the conversion processing table, the power transmission from the primary side to the secondary side can be performed. The maximum efficiency can be maintained.

  In the aspect of the invention, the reception processing unit receives information on a load current flowing through the load on the power receiving side as the power receiving side feedback information, and the transmission parameter setting unit is configured to drive the driving voltage of the primary coil. And at least one of the drive frequency is set as the transmission-side transmission parameter, and the conversion processing table outputs at least one of the drive voltage and the drive frequency of the primary coil based on the information on the load current. It is good.

  In this way, since at least one of the drive voltage and drive frequency of the primary coil is varied based on the load current information by the conversion processing table, power transmission from the primary side to the secondary side is maximized. Can be maintained.

  In the aspect of the invention, the reception processing unit further includes a storage unit that stores information received from the power receiving side, and the reception processing unit is information for specifying a load value detection method of the load. A certain load value detection method information may be received and written to the storage unit.

  In this way, the power transmission side can realize appropriate feedback control corresponding to the load value detection method on the power receiving side.

  In one aspect of the present invention, the load value detection method information is based on information on an output voltage to the load on the power receiving side and load current flowing in the load received as the power receiving side feedback information. A first load value detection method for detecting a value, and a second load value detection for detecting the load value on the power receiving side based on information on a load current flowing through the load on the power receiving side received as the power receiving side feedback information It may be information for specifying which of the detection methods.

  In this way, the power transmission side can realize appropriate feedback control corresponding to each of the load value detection methods on the power receiving side.

  According to another aspect of the present invention, a power transmission control device according to any one of the above, a power transmission unit that generates an AC voltage and supplies the AC voltage to the primary coil, and a power supply circuit that supplies a driving voltage to the power transmission unit, , Related to the power transmission device.

  Moreover, the other aspect of this invention is related with the electronic device containing the power transmission apparatus as described above.

  In another aspect of the present invention, the primary coil and the secondary coil are electromagnetically coupled to transmit power from the power transmission device to the power reception device, and supply power to the load of the power reception device. A power reception control device provided in the power reception device of a power transmission system, including a control unit that controls the power reception control device, wherein the control unit includes load information that is information for obtaining a load value of the load. A load information detection unit for detecting, and a transmission-side transmission parameter for obtaining an optimum load value at which the power transmission efficiency in the combination of the primary coil and the secondary coil is maximized for the load information detected by the load information detection unit Is related to a power reception control device including a transmission processing unit that transmits power to the power transmission device as power reception side feedback information for setting in the power transmission control device, and a power reception control unit that performs power reception control. That.

  According to another aspect of the present invention, based on the power receiving side feedback information transmitted to the power transmission side, the power transmission side sets power transmission side transmission parameters for obtaining an optimum load value at which the efficiency of power transmission is maximized. Since power transmission control is performed based on the side transmission parameter, it is possible to perform appropriate power transmission corresponding to the power receiving side feedback information.

  In another aspect of the present invention, the transmission processing unit may transmit load value detection method information for detecting load information, which is information for specifying a load value detection method for the load.

  In this way, on the power receiving side, proper feedback control corresponding to the load value detection method from the power transmitting side to the power receiving side is realized.

  In another aspect of the present invention, the transmission processing unit may receive at least one of information on output voltage to the load on the power receiving side and information on load current flowing in the load as the power receiving side feedback information. It is good also as transmitting to the power transmission device.

  If it does in this way, the power transmission apparatus which received the information of the output voltage to the load of the power receiving side and the load current flowing through the load as the power receiving side feedback information can perform appropriate power transmission corresponding to the change of the information.

  In another aspect of the present invention, the load information detection unit detects a load state before starting normal power transmission as the load information, and the transmission processing unit uses the load information as the power-receiving-side feedback information. It is good also as transmitting to.

  In this way, the amount of transmitted power immediately after the start of normal power transmission can be optimized.

  Another aspect of the present invention relates to a power reception device including the power reception control device described above and a power reception unit that converts an induced voltage of the secondary coil into a DC voltage.

  Another aspect of the invention relates to an electronic device including the power receiving device described above and a load to which power is supplied by the power receiving device.

  In another aspect of the present invention, the primary coil and the secondary coil are electromagnetically coupled to transmit power from the power transmission device to the power reception device, and supply power to the load of the power reception device. In the power transmission system, the power transmission control device that controls the power transmission device includes a power transmission side control unit that controls the power transmission control device, and the power transmission side control unit receives power reception side feedback information from the power reception device. A transmission parameter for setting a power transmission side transmission parameter for obtaining an optimum load value that maximizes the efficiency of power transmission in the combination of the primary coil and the secondary coil based on the reception processing unit and the power reception side feedback information A power reception control device that controls the power reception device, the power reception control device including a setting unit and a power transmission control unit that performs power transmission control based on the power transmission side transmission parameter. A power receiving side control unit that controls the load information detecting unit that detects load information that is information for obtaining a load value of the load, and the load information detected by the load information detecting unit. This is related to a non-contact power transmission system including a transmission processing unit that transmits the power transmission side feedback information to the power transmission device and a power reception control unit that controls the power transmission processing unit.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not necessarily.

1. Electronic Device FIG. 1A shows an example of an electronic device to which the contactless power transmission method of this embodiment is applied. A charger 500 (cradle), which is one of electronic devices, includes a power transmission device 10. In addition, the mobile phone 510 that is one of the electronic devices includes the power receiving device 40. In addition, the mobile phone 510 includes a display unit 512 such as an LCD, an operation unit 514 including buttons, a microphone 516 (sound input unit), a speaker 518 (sound output unit), and an antenna 520.

  Electric power is supplied to the charger 500 via the AC adapter 502, and this electric power is transmitted from the power transmitting device 10 to the power receiving device 40 by contactless power transmission. Thereby, the battery of the mobile phone 510 can be charged or the device in the mobile phone 510 can be operated.

  Note that the electronic device to which the present embodiment is applied is not limited to the mobile phone 510. For example, the present invention can be applied to various electronic devices such as wristwatches, cordless telephones, shavers, electric toothbrushes, wrist computers, handy terminals, portable information terminals, electric bicycles, and IC cards.

  As schematically shown in FIG. 1B, power transmission from the power transmission device 10 to the power reception device 40 is performed on the primary coil L1 (power transmission coil) provided on the power transmission device 10 side and on the power reception device 40 side. This is realized by electromagnetically coupling the secondary coil L2 (power receiving coil) formed to form a power transmission transformer. Thereby, non-contact power transmission becomes possible.

  In FIG. 1B, the primary coil L1 and the secondary coil L2 are, for example, air-core planar coils formed by winding coil wires in a spiral shape on a plane. However, the coil of the present embodiment is not limited to this, and any shape, structure, or the like may be used as long as the primary coil L1 and the secondary coil L2 can be electromagnetically coupled to transmit power.

  For example, in FIG. 1C, the primary coil L1 is formed by winding a coil wire spirally around the X axis with respect to the magnetic core. The same applies to the secondary coil L2 provided in the mobile phone 510. In this embodiment, the present invention can also be applied to a coil as shown in FIG. In the case of FIG. 1 (C), in addition to the coil wound around the X axis as the primary coil L1 and the secondary coil L2, a coil wound around the Y axis may be combined. Good.

2. FIG. 2 shows a configuration example of the power transmission device 10, the power transmission control device 20, the power reception device 40, and the power reception control device 50 included in the contactless power transmission system of the present embodiment. A power transmission-side electronic device such as the charger 500 of FIG. 1A includes the power transmission device 10 of FIG. In addition, a power receiving-side electronic device such as the mobile phone 510 can include the power receiving device 40 and a load 90 (main load). 2, for example, the primary coil L1 and the secondary coil L2 are electromagnetically coupled to transmit power from the power transmission device 10 to the power reception device 40 and supply power to the load 90. A contactless power transmission (non-contact power transmission) system is realized.

  The power transmission device 10 (power transmission module, primary module) can include a primary coil L1, a power transmission unit 12, a power supply circuit 18, and a power transmission control device 20. The power transmission device 10 and the power transmission control device 20 are not limited to the configuration in FIG. 2, and some of the components (for example, the primary coil) are omitted, or other components (for example, a waveform monitor circuit) are added. And various modifications such as changing the connection relationship are possible.

  The power transmission unit 12 generates an AC voltage from the drive voltage VF supplied from the power supply circuit 18 and supplies the AC voltage to the primary coil L1. Specifically, an AC voltage having a predetermined frequency is generated during power transmission, and an AC voltage having a different frequency according to data is generated and supplied to the primary coil L1 during data transfer. The power transmission unit 12 forms a resonance circuit together with, for example, a first power transmission driver that drives one end of the primary coil L1, a second power transmission driver that drives the other end of the primary coil L1, and the primary coil L1. At least one capacitor. Each of the first and second power transmission drivers included in the power transmission unit 12 is, for example, an inverter circuit (buffer circuit) configured by a power MOS transistor, and is controlled by the power transmission control device 20.

  The primary coil L1 (power transmission side coil) is electromagnetically coupled to the secondary coil L2 (power reception side coil) to form a power transmission transformer. For example, when power transmission is necessary, as shown in FIGS. 1A and 1B, a mobile phone 510 is placed on the charger 500, and the magnetic flux of the primary coil L1 passes through the secondary coil L2. Make it like this. On the other hand, when power transmission is unnecessary, the charger 500 and the mobile phone 510 are physically separated so that the magnetic flux of the primary coil L1 does not pass through the secondary coil L2.

  For example, the power supply circuit 18 converts an AC voltage obtained from a power source such as an external commercial AC power source into a DC voltage having a predetermined magnitude, and supplies the drive voltage VF to the power transmission unit 12 based on the supply voltage from the power source. To do.

  The power transmission control device 20 is a device that performs various controls of the power transmission device 10, and can be realized by an integrated circuit device (IC) or the like. The power transmission control device 20 can include a control unit 22, a storage unit 23, and a load state detection circuit 30. In addition, some implementations, such as abbreviate | omitting some of these components and adding another component, are possible.

  The control unit 22 (power transmission side) controls the power transmission device 10 and the power transmission control device 20. The control unit 22 can be realized by an ASIC circuit such as a gate array, or can be realized by a microcomputer and a program operating on the microcomputer. The control unit 22 controls the power transmission control device 20 that performs power transmission control using the power transmission unit 12, performs storage control of the storage unit 23, and controls the load state detection circuit 30. Specifically, by controlling the power transmission control device 20, various sequence control and determination processes necessary for power transmission, load state detection (data detection, foreign object detection, removal detection, etc.), frequency modulation, and the like are performed.

  The storage unit 23 (register unit) stores various types of information and can be realized by, for example, a RAM, a D flip-flop, or a nonvolatile memory such as a flash memory or a mask ROM.

  The load state detection circuit 30 (waveform detection circuit) detects the load state on the power receiving side (power receiving device or foreign object). This detection of the load state can be realized by detecting the waveform change of the induced voltage signal (coil end signal) of the primary coil L1. For example, when the load state (load current) on the power receiving side (secondary side) changes, the waveform of the induced voltage signal changes. The load state detection circuit 30 detects such a change in waveform and outputs a detection result (detection result information) to the control unit 22. Then, the control unit 22 determines a load state (load fluctuation, load level) on the power receiving side (secondary side) based on the load state detection information in the load state detection circuit 30.

  The power reception device 40 (power reception module, secondary module) includes a secondary coil L2, a power reception unit 42, a load modulation unit 46, a load information detection circuit (voltage / current detection circuit) 47, a power supply control unit 48, and a power reception control device 50. Can be included. The power reception device 40 and the power reception control device 50 are not limited to the configuration in FIG. 2, and some of the components (for example, the secondary coil) may be omitted or other components (for example, the load modulation unit) may be added. And various modifications such as changing the connection relationship are possible.

  The power receiving unit 42 converts the AC induced voltage of the secondary coil L2 into a DC voltage. This conversion can be realized by a rectifier circuit included in the power receiving unit 42.

  The load modulation unit 46 performs load modulation processing. Specifically, when desired data is transmitted from the power reception device 40 to the power transmission device 10, the load at the load modulation unit 46 (secondary side) is variably changed according to the transmission data, and the primary coil L1. The signal waveform of the induced voltage is changed.

  The power supply control unit 48 controls power supply to the load 90. That is, the power supply to the load 90 is turned on or off. Specifically, the level of the DC voltage from the power receiving unit 42 (rectifier circuit) is adjusted, a power supply voltage is generated, supplied to the load 90, and the battery 94 of the load 90 is charged. Note that the load 90 may not include the battery 94.

  The load information detection circuit (voltage / current detection circuit) 47 is composed of an A / D converter, for example, and detects load information that is information for obtaining the load value of the load 90 of the power receiving device 40. In the present embodiment, the load information detection circuit 47 uses, as load information, information on the output voltage to the load 90 of the power receiving device 40, that is, information on the secondary side load voltage, and information on load current flowing in the load 90, that is, information on the secondary side load current. To detect. The load information detected by the load information detection circuit 47 is a transmission-side transmission parameter for obtaining an optimum load value that maximizes the efficiency of power transmission in the combination of the primary coil L1 and the secondary coil L2. It is transmitted to the power transmission device 10 as power receiving side feedback information for setting. In the example shown in FIG. 2, it is provided between the power receiving unit 42 and the power supply control unit 48, but as the load information for determining the load value of the load 90 on the power receiving side, the secondary side load voltage and the secondary side Since it suffices if it is installed at a location where at least one of the side load currents can be detected, for example, it can be provided between the power supply control unit 48 and the load 90.

  The power reception control device 50 is a device that performs various controls of the power reception device 40 and can be realized by an integrated circuit device (IC) or the like. The power reception control device 50 can operate with a power supply voltage generated from the induced voltage of the secondary coil L2. The power reception control device 50 can include a control unit 52 and a storage unit 53.

  The control unit 52 (power reception side) controls the power reception device 40 and the power reception control device 50. The control unit 52 can be realized by an ASIC circuit such as a gate array, or can be realized by a microcomputer and a program operating on the microcomputer. The control unit 52 controls the power reception control device 50 that controls the power supply control unit 48 and performs storage control of the storage unit 53. Specifically, by controlling the power reception control device 50, various sequence control and determination processes necessary for position detection, frequency detection, load modulation, full charge detection, and the like are performed.

  The storage unit 53 (register unit) stores various types of information, and can be realized by, for example, a RAM, a D flip-flop, or a nonvolatile memory such as a flash memory or a mask ROM.

  The detection circuit 59 determines whether the positional relationship between the primary coil L1 and the secondary coil L2 is appropriate in the power receiving unit 42, for example, in order to appropriately transmit power from the power transmitting device 10 to the power receiving device 40. The power reception unit 42 detects the frequency (f1, f2) of the signal received from the power transmission side.

  In the present embodiment, the power transmission side control unit 22 includes a reception processing unit 34, a transmission processing unit 33, a transmission parameter setting unit 32, and a power transmission control unit 31.

  The reception processing unit 34 receives various types of information from the power receiving device 40, and receives power receiving side feedback information from the power receiving device 40 in the present embodiment. The reception processing unit 34 also receives load value detection method information that is information for specifying the load value detection method of the load 90 based on the power receiving side feedback information, and stores the load value detection method information in the storage unit 23. Write. The transmission processing unit 33 performs various types of information transmission processing on the power receiving device 40.

  The transmission parameter setting unit 32 sets a power transmission side transmission parameter for obtaining an optimum load value Xa that maximizes the power transmission efficiency in the combination of the primary coil L1 and the secondary coil L2, based on the power receiving side feedback information. . In the present embodiment, the transmission parameter setting unit 32 sets the power transmission side transmission parameter by a conversion processing table for converting the power receiving side feedback information into the power transmission side transmission parameter. Details of the conversion processing table of the transmission parameter setting unit 32 will be described later.

  The power transmission control unit 31 performs power transmission control based on various information received by the reception processing unit 34. In the present embodiment, the power transmission control unit 31 performs power transmission control based on the power transmission side transmission parameter.

  On the other hand, the power receiving side control unit 52 includes a reception processing unit 64, a transmission processing unit 65, a power reception control unit 66, and a load information detection unit 54.

  The reception processing unit 64 performs reception processing of various information from the power transmission device 10. The transmission processing unit 65 performs transmission processing of various information on the power transmission device 10. In the present embodiment, the transmission processing unit 65 obtains the optimum load value Xa that maximizes the efficiency of power transmission in the combination of the primary coil L1 and the secondary coil L2 from the load information detected by the load information detection unit 54. The power transmission side transmission parameters for the power transmission control device 20 are transmitted to the power transmission device 10 as power reception side feedback information. Also, the transmission processing unit 65 transmits load value detection method information, which is information for specifying the load value detection method of the load 90, to the power transmission side based on the power receiving side feedback information.

  The power reception control unit 66 performs power reception control. The load information detection unit 54 detects load information for obtaining the load value of the load 90. In the present embodiment, the load information detection unit 54 receives at least one of the information on the output voltage to the load 90 (battery 94) and the information on the load current flowing in the load 90 detected by the load information detection circuit 47. Detect as load information. Further, in order to be able to optimize the amount of transmitted power immediately after the start of normal power transmission, the load information detection unit 54 detects the load status such as the state of the battery 94 before the start of normal power transmission as load information, and performs transmission processing. The unit 65 may transmit the load information to the power transmission apparatus 10 as power receiving side feedback information.

  Further, in the present embodiment, even if the value X of the secondary load 90 changes after the start of normal power transmission, a transmission parameter setting unit is used to maintain power transmission from the primary side to the secondary side at the maximum efficiency. 32 sets the power transmission side transmission parameter so that the load value X of the power receiving device 40 obtained from the power receiving side feedback information approaches the optimum load value Xa. Specifically, the transmission parameter setting unit 32 sets at least one of the drive voltage Vin and the drive frequency fin of the primary coil L1 as the power transmission side transmission parameter. In other words, the transmission parameter setting unit 32 sets the power transmission side transmission parameter based on the power receiving side feedback information received by the reception processing unit 34.

  In the non-contact power transmission system shown in FIG. 2, the reception processing unit 34 of the power transmission device 10 receives the power receiving side feedback information during the regular authentication period after the start of normal power transmission, and the transmission parameter setting unit 32 receives the power receiving side feedback. Based on the information, power transmission side transmission parameters are set. That is, in the present embodiment, the power transmission control device 20 sets the drive voltage Vin of the primary coil L1 as the power transmission side transmission parameter based on the power reception side feedback information received in the periodic authentication period after the start of normal power transmission.

  In the present embodiment, when the power transmission apparatus 10 receives feedback information from the power receiving side, the power transmitting apparatus 10 is executed by a load modulation method depending on the load state detection circuit 30 provided on the power transmission side. The method is not limited to the load modulation method as long as information is transmitted and received in a non-contact manner. That is, the feedback information can be received from the power receiving side even by a constant feedback method using other communication means such as weak wireless or RF-ID. For example, as shown in FIG. 3, RF-ID tags 41 and 11 are provided on the power receiving side and the power transmission side, respectively, and always communicate, and the power transmission side feeds back from the power receiving side via these RF-ID tags 41 and 11. The information may be received, and the transmission parameter may be set so that the power transmission side has the maximum transmission efficiency ηmax based on the feedback information.

3. Operation of non-contact power transmission Now, when non-contact power transmission becomes widespread, it is expected that various types of secondary coils on the power receiving side will be put on the market. That is, since the outer shape and size of an electric device such as a mobile phone on the power receiving side are various, the outer shape and size of the secondary coil incorporated in the power receiving device of the electronic device are also varied accordingly. In addition, since the amount of electric power (wattage) and output voltage for contactless power transmission required by each electronic device are various, the inductance of the secondary coil and the like vary accordingly.

  For this reason, as shown in FIG. 4 (A), the normal power transmission of the power receiving device 40 (40A, 40B, 40C) that requires different amounts of power such as 0.5 W, 2.5 W, 15 W, etc. with one power transmitting device 10. When realizing the multi-charging to be performed, the power transmission device 10 transmits the transmission condition information necessary for normal power transmission such as the drive voltage VF of the primary coil L1 or the like during normal power transmission from the power receiving side to the power receiving device 40. Receive. Then, based on the received transmission condition information, after determining which power amount the power receiving devices 40A, 40B, and 40C are on the power receiving side, the power amounts corresponding to the power receiving devices 40A, 40B, and 40C are sent to the power receiving side. Normal power transmission.

  In this embodiment, when transmitting various information such as the transmission condition information from the power receiving side to the power transmitting side, as shown in FIG. 4B, a load that variably changes the load from the power receiving side according to the transmission data A carrier wave having a predetermined frequency is transmitted by the modulation method. That is, a component corresponding to a transmission signal including various information such as transmission condition information from the power receiving side is superimposed on the carrier wave, and the transmission signal is transmitted to the power transmission side.

  As described above, when various types of information communication are performed from the power receiving side to the power transmitting side by the load modulation method, EMI noise is generated when the power receiving device 40C having a power amount of 15 W performs transmission / reception of signals by load modulation at a high power of 15 W. Therefore, there is a concern of inducing a malfunction such as a malfunction of the power receiving device 40C.

  For this reason, in the present embodiment, at the stage before starting normal power transmission from the power transmission side to the power reception side, as shown in FIG. 5A, first, the power supply circuit 18 regardless of the magnitude of the power amount on the power reception side. Temporary power transmission is performed by controlling the control unit 22 of the power transmission control device 20 so that the first drive voltage VF1 that becomes the initial drive voltage is supplied to the power transmission unit 12. At this time, the amount of power supplied when the primary coil L1 is driven by the first drive voltage VF1 is supplied to the power receiving side as the minimum amount of power necessary for various information communications. In this manner, temporary power transmission for information communication between the power transmission device 10 and the power reception device 40 is started before normal power transmission from the power transmission device 10 to the power reception device 40 is started.

  When temporary power transmission is started, as shown in FIG. 5 (B), the second coil voltage becomes the primary coil drive voltage required for normal power transmission from the power receiving side requesting normal power transmission to the power receiving device 40. Various information including transmission condition information such as the driving voltage VF2 is transmitted. Then, when the power transmission side receives the transmission condition information and the like, the information indicating that the transmission is received is transmitted to the power receiving device 40 that is the transmission source of the transmission condition information, and the power reception side that is the transmission source is transmitted from the power transmission side. When the information is approved, a start frame is transmitted from the power receiving device 40 to the power transmitting device 10. In this way, the temporary power transmission before the start of normal power transmission is a basic of contactless power transmission between the power transmission side and the power receiving side, in addition to information communication such as transmission condition information between the power transmission side and the power receiving side. It is used for purposes such as exchanging information on settings (standards, coils, systems, safety functions, etc.) and detecting the position on the power receiving side.

  Thereafter, the control unit 22 supplies the second drive voltage VF2 that is the drive voltage corresponding to the transmission condition information and is larger than the first drive voltage VF1 at the time of temporary power transmission from the power supply circuit 18 to the power transmission unit 12. Control to do. And the power transmission control apparatus 20 drives the 1st coil L1 with the said 2nd drive voltage VF2 by controlling to supply the 2nd drive voltage VF2 to the power transmission part 12 from the power supply circuit 18, As illustrated in FIG. 5C, normal power transmission from the power transmission device 10 to the power reception device 40 is started.

  As described above, before starting normal power transmission, low wattage power necessary for information exchange as temporary power transmission is supplied to the power receiving device 40, and after starting normal power transmission, the power having the optimum magnitude for the power receiving device 40 is obtained. To increase. This temporary power transmission before the start of normal power transmission is not limited to information communication such as transmission condition information between the power transmission side and the power reception side, but also is a basic setting for contactless power transmission (standards) between the power transmission side and the power reception side. , Coils, systems, safety functions, etc.) for purposes such as exchanging information and detecting the position on the power receiving side. In the present embodiment, the second drive voltage VF2 is controlled to be larger than the first drive voltage VF1, but the second drive voltage VF2 is smaller than the first drive voltage VF1. Alternatively, the first drive voltage VF1 and the second drive voltage VF2 may be controlled to be the same.

As shown in FIG. 4A, the power receiving device 40 (40A, 40B, 40C) that is the power supply destination of the power transmitting device 10 has a method for detecting the load value of the load 90 (battery 94) depending on the model. Different. That is, in this embodiment, the first load value detection method and the second load value detection method are used as the load value detection method of the load 90 based on the power receiving side feedback information received by the reception processing unit 34 of the power transmission device 10. is there. In the first load value detection method, the load value on the power receiving side is detected based on the output voltage to the load 90 on the power receiving side and the information on the load current flowing in the load 90 received as power receiving side feedback information. In contrast, the second load value detection method, when the secondary load voltage V _2nd becomes a predetermined constant value, and the secondary load voltage V _2nd to be the constant value, as the power receiving side feedback information The load value on the power receiving side is detected based on the received information on the load current flowing through the load 90 on the power receiving side.

  Thus, since the load value detection method of the load 90 differs depending on the power receiving device 40 (40A, 40B, 40C), in the present embodiment, the power transmission side reception processing unit 34 uses the power receiving side feedback information to determine the load value of the load 90. The load value detection method information that is information for specifying the detection method is received, and the information is written in the storage unit 23. That is, in the information communication between the power transmission side and the power reception side shown in FIG. 5B, the power transmission side receives the load value detection method information from the power reception side, and then changes to each method of the load value detection method on the power reception side. By performing corresponding power transmission, the power transmission side can realize appropriate feedback control corresponding to the load value detection method on the power receiving side.

Further, after starting normal power transmission, for example, when the secondary connection load (battery 94 of the load 90) is of a rechargeable type, the value X of the load changes every moment. Therefore, when the load value X, which is the value of the load 90 when the primary coil L1 and the secondary coil L2 are combined, changes, the power transmission efficiency η at that time also changes as shown in FIG. Here, the load (load value X) is the reciprocal of the secondary side load resistance R _2nd , that is, (secondary side load voltage V _2nd ÷ secondary side load current I as shown in the following formula (1). _2nd ).
Load value X = 1 / R _2nd = 1 / (secondary load voltage V _2nd ÷ secondary load current I _2nd ) ... (1)

When the load value X at the maximum efficiency η _{max at which} the power transmission efficiency η is the maximum is the optimum load value Xa, the optimum load Xa is a constant determined by the combination of the primary coil L1 and the secondary coil L2 and the drive frequency. is there. Therefore, in order to maintain the power transmission efficiency η at the maximum efficiency η _max , the optimum load value Xa is maintained to be a constant value, that is, (secondary load voltage V _2nd ÷ secondary load). It can be seen that the reciprocal of the current I _2nd ), in other words, the ratio between the secondary side load voltage V _2nd and the secondary side load current I _2nd may be maintained constant.

Therefore, in the present embodiment, when the power transmission side receives the first load value detection method as the load value detection method of the load 90, as shown in FIG. As information (power-receiving-side feedback information), information on the secondary-side load voltage V _2nd that is the output voltage to the load 90 on the power-receiving side and the secondary-side load current I _2nd that is the load current flowing through the load 90 is received. Then, the transmission parameter setting unit 32 of the power transmission device 10 determines the optimum load value Xa that maximizes the efficiency of power transmission based on the power receiving side feedback information (secondary load voltage V _2nd , secondary load current I _2nd ). Transmission parameters (transmission-side transmission parameters) are set, and the transmission power from the primary side to the secondary side is adjusted as shown in FIG. 7B. In addition, when the power transmission side receives the second load value detection method as the load value detection method of the load 90, as shown in FIG. The secondary side load current I _2nd , which is the load current flowing through the side load 90, is received. Then, the transmission parameter setting unit 32 of the power transmission device 10 has the maximum power transmission efficiency based on the secondary side load voltage V _2nd and the power receiving side feedback information (secondary side load current I _2nd ) having a constant value. A transmission parameter (power transmission side transmission parameter) for obtaining the optimum load value Xa is set, and the transmission power from the primary side to the secondary side is adjusted as shown in FIG. 7B.

  In the present embodiment, the transmission power is adjusted using at least one of the driving voltage Vin and the driving frequency fin of the primary coil L1 as a transmission parameter. In this way, even if the load 90 on the secondary side changes after the start of normal power transmission, the transmission parameter setting unit 32 adjusts the transmission power by adjusting the drive voltage Vin of the primary coil L1, so from the primary side. The power transmission to the secondary side can be maintained at the maximum efficiency ηmax.

  Further, in the present embodiment, the transmission parameter setting unit 32 sets the power transmission side transmission parameter by the conversion processing table for converting the power receiving side feedback information into the power transmission side transmission parameter. That is, the power transmission control device 20 is characterized in that it holds a table for converting the feedback information on the power receiving side into a transmission parameter serving as power transmission control information, and determines the conversion processing table from the viewpoint of optimum load.

Specifically, when the first load value detection method is received as the load value detection method of the load 90, the reception processing unit 34 uses the secondary side load voltage V _2nd and the secondary side as the power receiving side feedback information. Information on the load current I _2nd is received. Then, the conversion processing table serving as the transmission parameter setting unit 32 is based on the information on the secondary side load voltage V _2nd and the secondary side load current I _{2nd serving} as power receiving side feedback information, and the driving voltage Vin of the primary coil L1 and At least one of the drive frequencies fin is set as a power transmission side transmission parameter and output. In addition, when the reception processing unit 34 receives the second load value detection method as the load value detection method of the load 90, it receives information on the secondary side load current I _2nd as the power reception side feedback information. And the conversion process table used as the transmission parameter setting unit 32 is based on the information on the secondary side load voltage V _2nd that is a predetermined constant value and the secondary side load current I _{2nd that} is the power receiving side feedback information. At least one of the drive voltage Vin and the drive frequency fin of L1 is set as a power transmission side transmission parameter and output. Thus, since the power transmission side transmission parameter is varied from the power receiving side feedback information by the conversion processing table, the power transmission from the primary side to the secondary side can be maintained at the maximum efficiency. The conversion processing table is determined based on the optimum load value Xa determined by the combination of the primary coil L1, the secondary coil L2, and the magnetic material.

  Note that the conversion processing table of the transmission parameter setting unit 32 may be realized by installing software such as a program for calculating power transmission side transmission parameters corresponding to each power receiving side feedback information. In addition, the conversion processing table may be configured by a ROM that stores power transmission side transmission parameters corresponding to each power receiving side feedback information in advance by a LUT (Lookup Table) circuit, or a logic circuit that realizes a function equivalent to the ROM. Good.

  Next, the operation of the conversion processing table serving as the transmission parameter setting unit 32 of this embodiment will be described with reference to the drawings. 8A and 8B show the operation of the conversion processing table when the reception processing unit 34 on the power transmission side receives the first load value detection method as the load value detection method of the load 90, FIG. 9A and 9B illustrate the operation of the conversion processing table when the power transmission side reception processing unit 34 receives the second load value detection method as the load value detection method of the load 90. FIG.

First, as a load value detection method for the load 90, a case where the power transmission side receives first load value detection method information and the load value detection method detects a load value by the first load value detection method will be described. In the first load value detection method, the load value on the power receiving side is detected based on the information on the output voltage to the load 90 on the power receiving side and the load current flowing in the load 90 received as power receiving side feedback information. At this time, when the load value X (Xc shown in FIG. 6) is larger than the optimum load value Xa, the secondary load voltage V _2nd at the load Xa is Va, and the secondary load current I _2nd is Ia. When the secondary load voltage V _2nd at the load Xc is Vc and the secondary load current I _2nd is Ic, at least one of Va> Vc or Ia <Ic is established. Since the load expressed by the ratio of the secondary side load voltage and the secondary side load current is Xc> Xa, the ratio of Vc and Ic at the load value Xc = 1 / (Vc / Ic) is set to the optimum load value Xa = 1 / In order to approach the ratio of Va and Ia in (Va / Ia), the conversion processing table of the transmission parameter setting unit 32 is a control for increasing Vc, that is, driving the primary coil L1, as shown in FIG. Control to increase the voltage Vin is performed. At this time, in order to approach the optimum load value Xa at which the maximum efficiency ηmax is obtained, at least one of the drive voltage Vin and the drive frequency fin of the primary coil L1 can be used as the transmission-side transmission parameter. In order to maintain the power transmission from the secondary side to the secondary side at the maximum efficiency ηmax, control for lowering the drive frequency fin may be performed.

On the other hand, when the load value X (Xb shown in FIG. 6) is smaller than the optimum load value Xa, the secondary load voltage V _2nd at the load Xa is Va, and the secondary load current I _2nd is Ia. When the secondary load voltage V _2nd at the load Xb is Vb and the secondary load current I _2nd is Ib, at least one of Va <Vb or Ia> Ib is established. Since the load expressed by the ratio of the secondary side load voltage and the secondary side load current is Xb <Xa, the ratio of Vb and Ib at the load value Xb = 1 / (Vb / Ib) is set to the optimum load value Xa = 1 / In order to approach the ratio of Va and Ia at (Va / Ia), the conversion processing table of the transmission parameter setting unit 32 controls the lowering of Vb, that is, the driving of the primary coil L1, as shown in FIG. Control to lower the voltage Vin is performed. At this time, in order to approach the optimum load value Xa at which the maximum efficiency ηmax is obtained, at least one of the drive voltage Vin and the drive frequency fin of the primary coil L1 can be used as the transmission-side transmission parameter. In order to maintain power transmission from the secondary side to the secondary side at the maximum efficiency ηmax, control for increasing the drive frequency fin may be performed.

  On the other hand, as the load value detection method of the load 90, when the power transmission side receives the second load value detection method information and the load value detection method detects the load value by the second load value detection method, power supply is performed. The output voltage from the control unit 48 to the load 90 is a predetermined constant value determined by the model of the power receiving device 40. For this reason, the load value on the power receiving side is detected based on the information on the output voltage to the load 90 having the predetermined constant value and the information on the load current flowing in the power receiving side load 90 received as the power receiving side feedback information.

At this time, when the load value X (Xc shown in FIG. 6) is larger than the optimum load value Xa, the secondary side load voltage V _2nd is set to a predetermined constant value Vcon (regardless of the magnitude of the load value X. In this embodiment, it is 4.0 V, for example). In contrast, the secondary load current I _2nd when the load Xa and Ia, the secondary-side load current I _2nd when the load Xc and Ic, secondary load voltage V _2nd are predetermined constant value Since Vcon, Ia <Ic is established. In the second load value detection method, since the secondary side load voltage V _2nd is a predetermined constant value Vcon, the optimum Vin when the load current information received from the power receiving side is Ic is sent to the transmission parameter setting unit 32. Judgment is made from a conversion processing table stored in advance, and the control of power transmission from the primary side to the secondary side is changed using the optimum Vin as a power transmission parameter. In this way, the conversion processing table of the transmission parameter setting unit 32 performs control to increase the output current Ic, that is, control to increase the drive voltage Vin of the primary coil L1, as shown in FIG. 9A. At this time, in order to approach the optimum load value Xa at which the maximum efficiency ηmax is obtained, at least one of the drive voltage Vin and the drive frequency fin of the primary coil L1 can be used as the transmission-side transmission parameter. In order to maintain the power transmission from the secondary side to the secondary side at the maximum efficiency ηmax, control for lowering the drive frequency fin may be performed. The transmission parameter setting unit 32 may store a plurality of conversion processing tables in advance, and a desired conversion processing table may be selected from these conversion processing tables.

Conversely, when the load value X (Xb shown in FIG. 6) is smaller than the optimum load value Xa is a secondary load current I _2nd load Xa and Ia, the secondary load current I _2nd when the load Xb Is Ib, the secondary load voltage V _2nd becomes a predetermined constant value Vcon, so that Ia> Ib is established. In the second load value detection method, since the secondary side load voltage V _2nd is a predetermined constant value Vcon, the optimum Vin when the load current information received from the power receiving side is Ib is sent to the transmission parameter setting unit 32. Judgment is made from a conversion processing table stored in advance, and the control of power transmission from the primary side to the secondary side is changed using the optimum Vin as a power transmission parameter. In this way, the conversion processing table of the transmission parameter setting unit 32 performs control to lower the output current Ib, that is, control to lower the drive voltage Vin of the primary coil L1, as shown in FIG. 9B. At this time, in order to approach the optimum load value Xa at which the maximum efficiency ηmax is obtained, at least one of the drive voltage Vin and the drive frequency fin of the primary coil L1 can be used as the transmission-side transmission parameter. In order to maintain power transmission from the secondary side to the secondary side at the maximum efficiency ηmax, control for increasing the drive frequency fin may be performed.

As described above, in the present embodiment, the transmission parameter setting unit 32 determines the load value X of the power receiving device 40 obtained based on the secondary side load voltage V _2nd and the secondary side load current I _2nd as the power receiving side feedback information. However, the transmission power transmission parameter is set to adjust the transmission power so as to approach the optimum load value Xa. In other words, the power transmission control device 20 that controls the power transmission device 10 is based on feedback information on the power receiving side received by the power transmission side, so that the load value X on the power receiving side makes the power transmission to the power receiving side the maximum efficiency ηmax. Power transmission control is performed so that

In this embodiment, the secondary side load voltage V _2nd , the secondary side load current I _2nd, and the proper power transmission corresponding to the change in the feedback information on the power receiving side, such as the secondary side load voltage I _2nd, is performed. It is possible to maintain power transmission to the maximum efficiency. For this reason, even if the secondary side connection load changes momentarily when the secondary side connection load is a rechargeable battery 94 or the like, the primary side load load is based on feedback information from the power reception side. By controlling the drive voltage Vin and the drive frequency fin, the load X can be adjusted to the optimum load value Xa corresponding to the change. Thereby, in the non-contact power transmission system of this embodiment, even if the load 90 on the secondary side fluctuates with time during power transmission to the secondary side, from the primary side to the secondary side corresponding to the fluctuation. It is possible to always maintain the transmission efficiency when transmitting power at the maximum efficiency ηmax.

  In the non-contact power transmission system of the present embodiment described above, after the normal power transmission of the power transmission device 10, the reception processing unit 34 receives the power receiving side feedback information, and the transmission parameter setting unit 32 is based on the feedback information. Although the power transmission side transmission parameter is set, the reception processing unit 34 may receive the power reception side feedback information before the start of normal power transmission. That is, the power transmission side reception processing unit 34 receives the power receiving side feedback information before the start of normal power transmission, and the transmission parameter setting unit 32 transmits the power transmission side transmission after the start of normal power transmission based on the power receiving side feedback information before the start of normal power transmission. A parameter may be set.

  In this other embodiment, at the stage before the start of normal power transmission from the power transmission side to the power reception side, first, as shown in FIG. 10A, first, the power supply circuit 18 regardless of the magnitude of the power amount on the power reception side. Temporary power transmission is performed by controlling the control unit 22 of the power transmission control device 20 so that the first drive voltage VF1 that becomes the initial drive voltage is supplied to the power transmission unit 12. Then, determination of the positional relationship between the primary coil L1 and the secondary coil L2 is performed.

  When temporary power transmission is started, as shown in FIG. 10 (B), transmission condition information such as the second drive voltage VF2 that is the drive voltage of the primary coil that is required for normal power transmission is started. Various information to be transmitted is transmitted from the power receiving side to the power transmitting side. At that time, in the other embodiment, the load value detection method information and the feedback information are transmitted from the power receiving side to the power transmitting side. When the power transmission side receives the transmission condition information and the like, the power transmission side transmits information indicating the reception to the power receiving device 40 that is a transmission source of the transmission condition information. Then, the power receiving device 40 transmits a start frame to the power transmitting device 10. In this way, the temporary power transmission before the start of normal power transmission is a basic of contactless power transmission between the power transmission side and the power receiving side, in addition to information communication such as transmission condition information between the power transmission side and the power receiving side. It is used for purposes such as exchanging information on settings (standards, coils, systems, safety functions, etc.) and detecting the position on the power receiving side.

  Thereafter, the control unit 22 supplies the second drive voltage VF2 that is the drive voltage corresponding to the transmission condition information and is larger than the first drive voltage VF1 at the time of temporary power transmission from the power supply circuit 18 to the power transmission unit 12. Control to do. And the power transmission control apparatus 20 drives the 1st coil L1 with the said 2nd drive voltage VF2 by controlling to supply the 2nd drive voltage VF2 to the power transmission part 12 from the power supply circuit 18, As shown in FIG. 10C, normal power transmission from the power transmission device 10 to the power reception device 40 is started. At this time, in order to be able to optimize the amount of transmitted power immediately after the start of normal power transmission, the load information detection unit 54 of the power reception control device 50 loads such as the state of the battery 94 of the load 90 before the start of normal power transmission. The situation may be detected as load information, and the transmission processing unit 65 may transmit the load information to the power transmission apparatus 10 as power receiving side feedback information.

  As described above, the reception processing unit 34 receives the power receiving side feedback information before starting the normal power transmission of the power transmission device 10, and the transmission parameter setting unit 32 performs the transmission after the normal power transmission starts based on the power receiving side feedback information before the normal power transmission starts. By setting the power transmission side transmission parameter, it is possible to perform proper power transmission corresponding to the power receiving side feedback information after the start of normal power transmission.

4). Detailed Configuration Example FIG. 11 shows a detailed configuration example of the present embodiment. In the configuration example illustrated in FIG. 11, the non-contact power transmission system when the first load value detection method is adopted as the load value detection method of the load 90 on the power receiving side based on the power receiving side feedback information is described. In the following, the components described in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The waveform monitor circuit 14 (rectifier circuit) generates an induced voltage signal PHIN for waveform monitoring based on the coil end signal CSG of the primary coil L1. For example, the coil end signal CSG which is an induced voltage signal of the primary coil L1 exceeds the maximum rated voltage of the IC of the power transmission control device 20, or becomes a negative voltage. The waveform monitor circuit 14 receives such a coil end signal CSG, generates an induced voltage signal PHIN for waveform monitoring, which is a signal that can be detected by the load state detection circuit 30 of the power transmission control device 20, and performs power transmission control. For example, output to the waveform monitor terminal of the apparatus 20. The display unit 16 displays various states of the contactless power transmission system (during power transmission, ID authentication, etc.) using colors, images, and the like.

  The oscillation circuit 24 generates a primary side clock. The drive clock generation circuit 25 generates a drive clock that defines the drive frequency. The driver control circuit 26 generates a control signal having a desired frequency based on the drive clock from the drive clock generation circuit 25, the frequency setting signal from the control unit 22, and the like, and the first and second power transmissions of the power transmission unit 12. It outputs to a driver and controls the 1st, 2nd power transmission driver.

  The load state detection circuit 30 shapes the induced voltage signal PHIN to generate a waveform shaping signal. For example, a square wave (rectangular wave) waveform shaping signal (pulse signal) that becomes active (eg, H level) when the signal PHIN exceeds a given threshold voltage is generated. The load state detection circuit 30 detects the pulse width information (pulse width period) of the waveform shaping signal based on the waveform shaping signal and the drive clock. Specifically, the pulse width information of the induced voltage signal PHIN is detected by receiving the waveform shaping signal and the drive clock from the drive clock generation circuit 25 and detecting the pulse width information of the waveform shaping signal.

  The load state detection circuit 30 is not limited to the pulse width detection method (phase detection method), and various methods such as a current detection method and a peak voltage detection method can be employed.

  The control unit 22 (power transmission control device) determines the load state (load fluctuation, load level) on the power receiving side (secondary side) based on the detection result in the load state detection circuit 30. For example, the control unit 22 determines the load state on the power receiving side based on the pulse width information detected by the load state detection circuit 30 (pulse width detection circuit), for example, data (load) detection, foreign matter (metal) Detection, removal (detachment) detection, etc. are performed. That is, the pulse width period, which is the pulse width information of the induced voltage signal, changes according to the change in the load state on the power receiving side. The control unit 22 can detect the load fluctuation on the power receiving side based on the pulse width period (a count value obtained by measuring the pulse width period).

  The power receiving unit 42 converts the AC induced voltage of the secondary coil L2 into a DC voltage. This conversion is performed by a rectifier circuit 43 included in the power receiving unit 42.

  The load modulation unit 46 performs load modulation processing. Specifically, when desired data is transmitted from the power reception device 40 to the power transmission device 10, the load at the load modulation unit 46 (secondary side) is variably changed according to the transmission data, and the primary coil L1. The signal waveform of the induced voltage is changed. For this purpose, the load modulation unit 46 includes a resistor RB3 and a transistor TB3 (N-type CMOS transistor) provided in series between the nodes NB3 and NB4. The transistor TB3 is on / off controlled by a signal P3Q from the control unit 52 of the power reception control device 50. When performing load modulation by controlling on / off of the transistor TB3, the transistor TB2 of the power feeding control unit 48 is turned off, and the load 90 is not electrically connected to the power receiving device 40.

  The load information detection circuit (voltage / current detection circuit) 47 is composed of, for example, an A / D converter or the like, and includes a voltage detection circuit 47v that detects an output voltage (secondary load voltage) to the load 90, and a power receiving device 40. And a current detection circuit 47a that detects a load current (secondary load current) flowing through the load 90. The voltage information and current information detected by the voltage detection circuit 47v and the current detection circuit 47a are transmitted to the control unit 52 via the load information detection unit 54 of the power reception control device 50, respectively. As described above, the load information detection circuit (voltage / current detection circuit) 47 detects information on the output voltage to the load 90 and the load current flowing in the load 90, and sends the detection signal to the control unit 52 of the power reception control device 50. Send to. And the control part 52 transmits these information to the power transmission apparatus 10 as receiving side feedback information by performing on-off control of the transistor TB3 of the load modulation part 46, and performing load modulation. Thus, in this embodiment, based on the power receiving side feedback information detected by the load information detection circuit 47, the optimum load value that maximizes the efficiency of power transmission in the combination of the primary coil L1 and the secondary coil L2. Is set in the power transmission control device 20.

  The power supply control unit 48 controls power supply to the load 90. The regulator 49 adjusts the voltage level of the DC voltage VDC obtained by the conversion in the rectifier circuit 43 to generate the power supply voltage VD5 (for example, 5V). The power reception control device 50 operates by being supplied with the power supply voltage VD5, for example.

  The transistor TB2 (P-type CMOS transistor, power supply transistor) is controlled by a signal P1Q from the control unit 52 of the power reception control device 50. Specifically, the transistor TB2 is turned off during the negotiation process and the setup process, and is turned on after the normal power transmission is started.

  The position detection circuit 56 determines whether the positional relationship between the primary coil L1 and the secondary coil L2 is appropriate. The oscillation circuit 58 generates a secondary clock. The frequency detection circuit 60 detects the frequency (f1, f2) of the signal CCMPI. The full charge detection circuit 62 detects whether or not the battery 94 (secondary battery) of the load 90 is in a fully charged state (charged state).

  The load 90 can include a charge control device 92 that performs charge control of the battery 94 and the like. The charge control device 92 (charge control IC) can be realized by an integrated circuit device or the like. Note that, like a smart battery, the battery 94 itself may have the function of the charging control device 92.

  Next, as a detailed configuration example of the present embodiment, a non-contact power transmission system when the second load value detection method is adopted as the load value detection method of the load 90 on the power receiving side based on the power receiving side feedback information. This will be described with reference to FIG. In the following, the components described in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  When the second load value detection method is adopted as the load value detection method of the load 90 on the power receiving side, the power receiving device 40 of the first load value detection method is different from the configuration and installation location of the load information detection circuit 47. Is different. That is, in the power receiving device 40 that employs the first load value detection method, as shown in FIG. 11, the load information detection circuit 47 is provided between the load modulation unit 46 and the power supply control unit 48. In the power receiving device 40 that employs the load value detection method 2, a load information detection circuit 47 is provided between the power supply control unit 48 and the load 90, as shown in FIG. 12. For this reason, since the output voltage of the power supply control device 48 that is output after passing through the regulator 49 of the power supply control device 48 becomes a predetermined constant value, the power receiving device 40 that employs the second load value detection method is the load information. The detection circuit 47 includes only a current detection circuit 47 a that detects a load current (secondary load current) flowing from the power receiving device 40 to the load 90.

  In the power receiving device 40 that employs the second load value detection method, the current information detected by the current detection circuit 47 a is transmitted to the control unit 52 via the load information detection unit 54 of the power reception control device 50. As described above, the load information detection circuit 47 detects information on the load current flowing through the load 90 and transmits the detection signal to the control unit 52 of the power reception control device 50. And the control part 52 transmits the information of load current to the power transmission apparatus 10 as receiving side feedback information by carrying out load modulation by carrying out on-off control of transistor TB3 of the load modulation | alteration part 46. FIG. Thus, in this embodiment, based on the power receiving side feedback information detected by the load information detection circuit 47, the optimum load value that maximizes the efficiency of power transmission in the combination of the primary coil L1 and the secondary coil L2. Is set in the power transmission control device 20.

  11 and 12 described above, data communication from the power transmission side to the power reception side is realized by frequency modulation, and data communication from the power reception side to the power transmission side is realized by load modulation.

  Specifically, as illustrated in FIG. 13A, for example, when the data “1” is transmitted to the power receiving side, the power transmission unit 12 generates an alternating voltage of the frequency f1 and the data “0”. Is transmitted, an AC voltage having a frequency f2 is generated. Then, the frequency detection circuit 60 on the power receiving side detects the change in the frequency, thereby discriminating the data “1” and “0”. Thereby, data communication by frequency modulation from the power transmission side to the power reception side is realized.

  On the other hand, the power receiving side load modulation unit 46 variably changes the power receiving side load according to the data to be transmitted, and changes the signal waveform of the induced voltage of the primary coil L1 as shown in FIG. Let For example, when data “1” is transmitted to the power transmission side, the power reception side is set to a high load state, and when data “0” is transmitted, the power reception side is set to a low load state. Then, the load state detection circuit 30 on the power transmission side detects data “1” and “0” by detecting the change in the load state on the power reception side. Thereby, data communication by load modulation from the power receiving side to the power transmission side is realized.

  In FIGS. 13A and 13B, data communication from the power transmission side to the power reception side is realized by frequency modulation, and data communication from the power reception side to the power transmission side is realized by load modulation. Other modulation schemes or other schemes may be employed.

5). Details of Operations on Power Transmission Side and Power Reception Side Next, details of operations on the power transmission side and the power reception side will be described using the flowchart of FIG. In FIG. 14, the left column is a power transmission side processing flow, and the right column is a power reception side processing flow.

  When the power is turned on and powered on, the power transmission side waits for a predetermined time (step S201), and then performs temporary power transmission before starting normal power transmission (step S202). This temporary power transmission is temporary power transmission for landing detection, position detection, and the like. That is, power transmission is performed to detect whether or not the electronic device is placed on the charger and, if so, whether or not the electronic device is placed at an appropriate position.

  Due to temporary power transmission from the power transmission side, the power reception side is powered on from the stopped state (step S221) (step S222), and the power reception control device 50 is reset to power-on. Then, the power reception control device 50 sets the signal P1Q to the H level, whereby the transistor TB2 (power supply transistor) of the power supply control unit 48 is turned off (step S223), and the electrical connection with the load 90 is established. Blocked.

  Next, after determining the positional relationship (position level) between the primary coil L1 and the secondary coil L2, the power receiving side creates an ID authentication frame and transmits it to the power transmitting side (step S224). In the present embodiment, in step S224, the load value detection method information is transmitted from the power receiving side to the transmitting side.

  When the power transmission side receives the ID authentication frame (step S204), the power transmission side performs authentication processing on the power reception side based on the ID authentication frame to determine whether or not the authentication has been established (step S205). Further, based on the received load value detection method information, for example, which of the conversion processing tables in FIG. 8A and FIG. 8B is used is switched.

  If authentication is not established in step S205, power transmission is stopped and the process returns to step S201. On the other hand, if authentication is established, a response frame of the ID authentication frame is transmitted to the power receiving side (step S206).

  When the power receiving side receives the response frame from the power transmission side (step S225), the power receiving side performs an authentication process on the power transmission side based on the response frame received from the power transmission side to determine whether or not the authentication is established (step S226). . When authentication is established in step S226, a start frame is transmitted to the power transmission side (step S227). On the other hand, if the authentication is not established, the start frame is not transmitted to the power transmission side. As a result, the power transmission side times out and power transmission is stopped, whereby the power reception side is stopped (step S221).

  Thereafter, when the power transmission side receives the start frame (step S207), it turns on periodic authentication (step S208) and starts normal power transmission (full-scale power transmission) (step S209). In the present embodiment, the power transmission side receives the load value detection method information before starting normal power transmission and writes the load value detection method information in the storage unit 23. Therefore, appropriate feedback control corresponding to the load value detection method on the power receiving side can be realized.

  When the power transmission side starts normal power transmission, the power receiving side starts receiving power, turns on the transistor TB2, and supplies power to the load 90 (step S228). Thereby, for example, the battery 94 is charged. The power receiving side turns on the periodic authentication after the start of normal power transmission (step S229). And it is judged whether it is a periodical authentication period (step S230), and when it is a periodical authentication period, regular load modulation is performed and feedback information is transmitted to the power transmission side as periodical authentication data (step S231). . Specifically, the feedback information is transmitted by turning on and off the transistor TB3 of the load modulation unit 46 of FIG. 10 in a predetermined pattern in the periodic authentication period. In this embodiment, the power transmission side sets a power transmission side transmission parameter for obtaining an optimum load value that maximizes the efficiency of power transmission based on the feedback information, and performs power transmission control based on the power transmission side transmission parameter. Do. For this reason, even if the load on the power receiving side fluctuates, proper power transmission corresponding to the power receiving side feedback information can be performed.

  After receiving the feedback information to the power transmission side, the power receiving side determines whether or not the battery 94 is fully charged (step S232), and when full charge is detected, turns off the transistor TB2 and turns off the load. Power supply to 90 is stopped (step S233). Also, periodic authentication is turned off (step S234). Then, a full charge detection command (save frame) informing the detection of full charge is transmitted to the power transmission side (step S235).

  On the other hand, the power transmission side determines whether periodic authentication has been established after starting normal power transmission (step S210). And when regular authentication is not materialized, power transmission is stopped and it returns to Step S201. On the other hand, if the power transmission side detects the establishment of periodic authentication in step S210, the power transmission side performs removal detection and foreign object detection (steps S212 and S213). .

  Next, the power transmission side determines whether or not a full charge detection command (save frame) is received from the power reception side (step S213). When the full charge detection command is received, the periodic authentication is turned off (step S214), the power transmission is stopped, and the process returns to step S201.

6). Periodic authentication Next, periodic authentication will be described. Periodic authentication is to detect a so-called foreign object hijacking state by intermittently changing the load on the power receiving side and detecting the intermittent load fluctuation on the power transmission side in each periodic authentication period of the normal power transmission period. is there.

  That is, for example, a large-sized metal foreign object may be inserted between the primary coil L1 and the secondary coil L2 after the negotiation process and the setup process are completed and normal power transmission (full-scale power transmission) is started. Metal foreign matter having a small to medium area can be detected by monitoring the induced voltage signal of the primary coil L1. However, when a large-sized metal foreign object is inserted, the metal foreign object appears to the power transmission side as the same load as the main load. Therefore, even when the negotiation process and the like are completed, the power transmission side regards the metal foreign object as a load, continues power transmission, and power transmission energy from the power transmission side continues to be consumed by the metal foreign object. As a result, a problem arises in that the metal foreign matter becomes a high temperature. In this embodiment, a phenomenon in which a large-sized metal foreign object or the like replaces the original power-receiving device and power is continuously transmitted to the foreign object is referred to as a “takeover state” in this embodiment.

  In order to detect such a hijacking state, in FIG. 15, the load on the power receiving side is intermittently changed in the periodic authentication period TA. Specifically, the load modulation signal P3Q is intermittently changed to turn on / off the transistor TB3 of the load modulation unit 46 intermittently. When the transistor TB3 is turned on, the power receiving side has a relatively high load (small impedance), and when the transistor TB3 is turned off, the power receiving side has a relatively low load (high impedance). The load state detection circuit 30 on the power transmission side detects this intermittent load fluctuation on the power reception side. For example, a change in load on the power receiving side is detected by detecting a change in the pulse width period of the coil end signal.

  In this embodiment, feedback information for setting transmission parameters is transmitted from the power reception side to the power transmission side during the periodic authentication period. That is, the reception processing unit 34 receives the power receiving side feedback information during the periodic authentication period after the start of normal power transmission, and the transmission parameter setting unit 32 sets the power transmission side transmission parameters based on the power receiving side feedback information.

  In this way, even when the load value of the battery 94 of the load 90 changes every moment during the discharge / charge after the start of normal power transmission, the signal transmission by the load fluctuation in the periodic authentication period TA can be used from the power receiving side. Feedback information can be transmitted to the power transmission side. For this reason, the power transmission apparatus 10 can set the power transmission side transmission parameter for obtaining the optimum load value that maximizes the efficiency of power transmission based on the power reception side feedback information received from the power reception side. Then, the power transmission device 10 can perform power transmission control based on the power transmission-side transmission parameter, and perform appropriate power transmission while maintaining the maximum efficiency.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described together with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term anywhere in the specification or the drawings. All combinations of the present embodiment and the modified examples are also included in the scope of the present invention. Also, power transmission control device, power transmission device, power reception control device, configuration and operation of power reception device, load state determination method using threshold information, system information verification method, negotiation setup command processing method, The load state detection method and the like are not limited to those described in this embodiment, and various modifications can be made.

1A, 1B, and 1C are explanatory diagrams of contactless power transmission. 1 is a configuration example of a power transmission device, a power transmission control device, a power reception device, and a power reception control device of the present embodiment. The structural example of the power transmission apparatus, power transmission control apparatus, power receiving apparatus, and power reception control apparatus of other embodiment. FIG. 4A is an operation explanatory diagram of normal power transmission to a plurality of power receiving devices by one power transmission device, and FIG. 4B is an explanatory diagram of data transfer by load modulation according to the present embodiment. FIG. 5A, FIG. 5B, and FIG. 5C are explanatory diagrams of the operation of this embodiment. Explanatory drawing of the processing sequence of non-contact electric power transmission of this embodiment. 7A and 7B are explanatory diagrams of the operation of this embodiment. FIG. 8A and FIG. 8B are explanatory diagrams of the operation of the conversion processing table of this embodiment. FIG. 9A and FIG. 9B are explanatory diagrams of the operation of the conversion processing table of this embodiment. FIG. 10A, FIG. 10B, and FIG. 10C are explanatory diagrams of the operation of another embodiment. The detailed structural example of the power transmission apparatus of this embodiment, a power transmission control apparatus, a power receiving apparatus, and a power reception control apparatus. The detailed structural example of the power transmission apparatus of other embodiment, a power transmission control apparatus, a power receiving apparatus, and a power reception control apparatus. 13A and 13B are explanatory diagrams of data transfer by frequency modulation and load modulation. The flowchart for demonstrating the operation | movement of this embodiment. The figure for demonstrating periodical authentication.

Explanation of symbols

L1 primary coil, L2 secondary coil, f1 first frequency, f2 second frequency,
VF drive voltage, VF1 first drive voltage, VF2 second drive voltage 10 power transmission device, 12 power transmission unit, 14 waveform monitor circuit, 18 power supply circuit,
20 power transmission control device, 22 control unit (power transmission side), 23 storage unit, 24 oscillation circuit,
25 drive clock generation circuit, 26 driver control circuit, 30 load state detection circuit,
31 transmission control unit, 32 transmission parameter setting unit, 33 transmission processing unit,
34 reception processing unit, 40 power receiving device, 42 power receiving unit, 43 rectifier circuit,
46 load modulation unit, 47 load information detection circuit, 48 power supply control unit,
50 power reception control device, 52 control unit (power reception side), 53 storage unit, 54 load information detection unit,
56 position detection circuit, 58 oscillation circuit, 59 detection circuit, 60 frequency detection circuit,
62 full charge detection circuit, 64 reception processing unit, 65 transmission processing unit, 66 power reception control unit,
90 load, 92 charge control device, 94 battery

Claims (24)

The primary coil and the secondary coil are electromagnetically coupled to transmit power from the power transmission device to the power reception device, and control the power transmission device of the non-contact power transmission system that supplies power to the load of the power reception device A power transmission control device,
A control unit for controlling the power transmission control device;
The controller is
A reception processing unit that receives power-receiving-side feedback information from the power receiving device;
A transmission parameter setting unit for setting a power transmission side transmission parameter for obtaining an optimum load value that maximizes the efficiency of power transmission in the combination of the primary coil and the secondary coil, based on the power receiving side feedback information;
A power transmission control unit that performs power transmission control based on the power transmission side transmission parameter;
A power transmission control device comprising: In claim 1,
The transmission parameter setting unit
The power transmission control device, wherein the power transmission side transmission parameter is set so that a load value of the load of the power receiving device obtained from the power receiving side feedback information approaches the optimum load value. In claim 1 or 2,
The transmission parameter setting unit
At least one of the drive voltage and drive frequency of the primary coil is set as the power transmission side transmission parameter. In any one of Claims 1 thru | or 3,
The reception processing unit
Receiving the power receiving side feedback information after starting normal power transmission of the power transmission device;
The transmission parameter setting unit
The power transmission control device, wherein the power transmission side transmission parameter is set based on the power reception side feedback information. In claim 4,
The reception processing unit
The power receiving side feedback information is received in the periodic authentication period after the start of normal power transmission,
The transmission parameter setting unit
The power transmission control device, wherein the power transmission side transmission parameter is set based on the power reception side feedback information. In any one of Claims 1 thru | or 3,
The reception processing unit
Receiving the power receiving side feedback information before starting normal power transmission of the power transmission device,
The transmission parameter setting unit
A power transmission control device that sets the power transmission side transmission parameter after the start of normal power transmission based on the power receiving side feedback information before the start of normal power transmission. In any one of Claims 1 thru | or 6.
The reception processing unit
The power transmission control device, wherein at least one of information on output voltage to the load on the power receiving side and information on load current flowing in the load is received as the power receiving side feedback information. In claim 7,
The transmission parameter setting unit
The power transmission control device, wherein the power transmission side transmission parameter is set so that a load value of the load obtained based on the power receiving side feedback information approaches the optimum load value. In claim 8,
The transmission parameter setting unit
When the load value is smaller than the optimum load value, at least one of control for decreasing the drive voltage of the primary coil and control for increasing the drive frequency of the primary coil is performed. In claim 8,
The transmission parameter setting unit
When the load value is larger than the optimum load value, at least one of control for increasing the drive voltage of the primary coil and control for decreasing the drive frequency of the primary coil is performed. In any one of Claims 1 thru | or 10.
The transmission parameter setting unit
The power transmission control device, wherein the power transmission side transmission parameter is set by a conversion processing table for converting the power receiving side feedback information into the power transmission side transmission parameter. In claim 11,
The reception processing unit
As the power receiving side feedback information, information on the output voltage to the load on the power receiving side and the load current flowing in the load is received,
The transmission parameter setting unit
Setting at least one of the drive voltage and drive frequency of the primary coil as the power transmission side transmission parameter;
The conversion processing table is
A power transmission control device that outputs at least one of the drive voltage and the drive frequency of the primary coil based on information on the output voltage and the load current. In claim 11,
The reception processing unit
As the power receiving side feedback information, information on the load current flowing through the load on the power receiving side is received,
The transmission parameter setting unit
Setting at least one of the drive voltage and drive frequency of the primary coil as the power transmission side transmission parameter;
The conversion processing table is
A power transmission control device that outputs at least one of the drive voltage and the drive frequency of the primary coil based on information on the load current. In any one of Claims 1 thru | or 13.
A storage unit for storing information received from the power receiving side;
The reception processing unit
A power transmission control device, wherein load value detection method information, which is information for specifying a load load value detection method, is received and written in the storage unit. In claim 14,
The load value detection method information is
A first load value detection method for detecting the load value on the power receiving side based on the output voltage to the load on the power receiving side received as the power receiving side feedback information and information on the load current flowing in the load;
A second load value detection method for detecting the load value on the power receiving side based on information on the load current flowing in the load on the power receiving side received as the power receiving side feedback information;
It is the information for specifying which detection method of which is, The power transmission control apparatus characterized by the above-mentioned. A power transmission control device according to any one of claims 1 to 15,
A power transmission unit that generates an alternating voltage and supplies the alternating voltage to the primary coil;
And a power supply circuit that supplies a driving voltage to the power transmission unit.   An electronic device comprising the power transmission device according to claim 16. The power receiving device of the contactless power transmission system that electromagnetically couples the primary coil and the secondary coil to transmit power from the power transmitting device to the power receiving device and supplies power to the load of the power receiving device. A power reception control device provided,
A control unit for controlling the power reception control device;
The controller is
A load information detection unit that detects load information that is information for obtaining a load value of the load;
In the power transmission control device, the load information detected by the load information detection unit is used as a transmission side transmission parameter for obtaining an optimum load value that maximizes the power transmission efficiency in the combination of the primary coil and the secondary coil. A transmission processing unit for transmitting to the power transmission device as power receiving side feedback information for setting;
A power reception control unit for performing power reception control;
A power reception control device comprising: In claim 18,
The transmission processing unit
A power reception control device that transmits load value detection method information that is information for specifying a load value detection method of the load. In claim 18 or 19,
The transmission processing unit
The power reception control device, wherein at least one of information on output voltage to the load on the power reception side and information on load current flowing in the load is transmitted to the power transmission device as the power reception side feedback information. In any of claims 18 to 20,
The load information detection unit
Detecting the load status before starting normal power transmission as the load information,
The transmission processing unit
The power reception control device, wherein the load information is transmitted to the power transmission device as the power reception side feedback information. A power reception control device according to any one of claims 18 to 21,
A power receiving unit that converts an induced voltage of the secondary coil into a DC voltage;
A power receiving device comprising: A power receiving device according to claim 22;
A load to which power is supplied by the power receiving device;
An electronic device comprising: A non-contact power transmission system that electromagnetically couples a primary coil and a secondary coil to transmit power from a power transmission device to a power reception device and supplies power to a load of the power reception device,
The power transmission control device for controlling the power transmission device is:
Including a power transmission side control unit for controlling the power transmission control device,
The power transmission side control unit
A reception processing unit that receives power-receiving-side feedback information from the power receiving device;
A transmission parameter setting unit for setting a power transmission side transmission parameter for obtaining an optimum load value that maximizes the efficiency of power transmission in the combination of the primary coil and the secondary coil based on the power receiving side feedback information;
A power transmission control unit that performs power transmission control based on the power transmission side transmission parameter;
Including
The power reception control device for controlling the power reception device is:
A power receiving side control unit for controlling the power receiving control device;
The power receiving side control unit
A load information detection unit that detects load information that is information for obtaining a load value of the load;
A transmission processing unit that transmits the load information detected by the load information detection unit to the power transmission device as the power receiving side feedback information;
A power reception control unit for controlling the power transmission processing unit;
A contactless power transmission system comprising:

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